Effect of Interface Morphology on Tensile Properties of Carbon Steel Sheet with Sandwich Structure

Abstract

Tensile properties of steel sheet with the sandwich mesostructure are studied to clarify the influence of interface morphology. The 0.05%C and the 0.45%C steel flat plates with the same volume fractions to each other are stacked as the surface and the center layers, respectively, and the stacked sheets are welded by hot compression in plain strain condition. Additionally, before the stacking, V‐shaped grooves are cut along the direction perpendicular to the tensile axis on the surfaces, where the different two carbon steel sheets contact in the stacking. The compression of the grooved sheets realizes the sandwich mesostructure with largely waved interfaces. The microstructures of the surface and the center layers are ferrite–pearlite and lath martensite, respectively. The tensile test at room temperature clarifies that the grooved interface deteriorates the fracture stress. The fracture occurrs where the local tensile stress increases due to the restraint effect by the interface.